In fact, Frimpong's omission had been raised earlier in the day, with Gunners manager Arsene Wenger telling the club's official website that the player was not in the squad because "he is still short of competition".

However, it is not the first time Frimpong has caused controversy on Twitter.

He was previously charged with improper conduct and fined £6,000 by the FA after a comment aimed at a Tottenham fan in 2012, who he branded "scum y**".